Mary MacCornack Forsythe (May 23, 1920 – September 6, 2007) was an American politician and music teacher.
Born in Whitehall, Wisconsin, Forsythe graduated from Whitehall High School and then received her bachelor's degree from St. Olaf College in music. She taught music in elementary and high school. Forsythe lived in Edina, Minnesota. Forsythe served in the Minnesota House of Representatives from 1973 to 1991 as a Republican. She died in Saint Paul, Minnesota.